1, topdressing at seedling stage: corn does not need much fertilizer at seedling stage. Generally speaking, topdressing should be applied lightly from seedling stage to jointing stage. In order to reduce labor input, common seedling fertilizer and jointing fertilizer can also be used as topdressing. Available nitrogen fertilizer is the main topdressing at seedling stage. At the same time, according to the growth of corn, phosphorus, potassium fertilizer and decomposed agricultural fertilizer can be applied appropriately. When the leaves of corn are 3-4, topdressing can be used. 500 kg of decomposed farmyard manure+2-3 kg of urea were applied to common corn fields, and 65,438 kg of decomposed farmyard manure+4-5 kg of urea were applied to wheat and corn fields, which was insufficient to supplement the base fertilizer. Topdressing at seedling stage depends on the growth and development of maize. Slow-growing and aging people should wear coats, while energetic people don't have to wear coats.

2. Topdressing at jointing stage: The main purpose of topdressing is to increase and prolong the photosynthetic area of leaves and ensure the development of maize roots, stems and ears. Topdressing should also be based on available nitrogen fertilizer. It is usually applied to 7-9 maize leaves in the field. Urea 10- 15kg can be topdressing per mu in ordinary corn fields, but phosphorus and potassium fertilizer are insufficient. 7~ 10kg of NPK compound fertilizer can be applied per mu in the plot, and a proper amount of decomposed agricultural fertilizer has a better effect. Three-ear plastic surgery: ear plastic surgery is generally carried out at the stage of big horn mouth. Its main purpose is to promote the differentiation of spikelets and florets, make spikelets bigger, have more grains and more upper leaves. At this time, the available nitrogen fertilizer should be the main fertilizer, but due to the large amount of fertilizer required by corn, urea or high nitrogen and low phosphorus compound fertilizer can be used per mu. Topdressing soil 15- 17 kg, sufficient base fertilizer and high fertility. Average area 18-20kg, and topdressing can reach 22-25kg in areas with insufficient base fertilizer or poor fertility. In addition, if the planting density is high and the use density is low, the amount of topdressing can be reduced.

3. Top dressing of grain: Top dressing of grain is generally carried out at the filling stage of corn, because corn needs more nitrogen and phosphorus from heading to maturity, accounting for about 40% of the whole growth period. Topdressing can prevent late and premature senescence of maize, prolong photosynthesis of leaves and increase grain weight per ear. Achieve the effect of increasing production. The leaves were sprayed with 2% nitrogen and phosphorus mixed solution and 75- 100 kg water and fertilizer solution per mu.

The above is about corn planting and fertilization skills. I hope it helps you.